The present invention relates generally to an automated data storage library including media storage units, and more specifically to a communication interface for data transfer to and from each media storage unit.
A typical data storage library such as a tape library includes an array of media storage unit (e.g., tape cartridge) storage slots, and one or more media drives (e.g., tape drives) for data transfer to and from the tape cartridges. A central cartridge inventory is maintained by a library controller, so that logical requests for a particular tape drive and cartridge may be translated by the library controller into physical tape cartridge and drive locations, and electromechanical operations.
Conventionally, in response to a host xe2x80x9cmove media cartridge to drivexe2x80x9d command for transferring data to and from the tape cartridge, the tape cartridge must be picked and moved, to be loaded to a tape drive for reading or writing data to the tape cartridge. The data in the tape cartridge can include cartridge information such as directory information, file information, diagnostic information, cartridge history information, remaining life time of the cartridge, etc. related to each tape cartridge. The library includes a robotic arm that is elevated and rotated to a particular cartridge storage slot. A picker-gripper mechanism of the arm then xe2x80x9cpicksxe2x80x9d and xe2x80x9cgripsxe2x80x9d a tape cartridge stored in the slot and moves the tape cartridge out of the slot and into a temporary transport slot of the arm. The robotic arm is then commanded to perform a second rotation/elevation operation in order to present the retrieved tape cartridge to a loading tray of the selected tape drive, and the tape drive then loads the tape cartridge and threads the tape in the cartridge for recording/playback operations, following initial setup and calibration routines conventional with tape drives.
A disadvantage of the conventional libraries for data transfer to/from a tape cartridge is the time delay incurred between receiving the tape cartridge request and having the cartridge ready for user data operations at the selected tape drive. Further, frequent picking of cartridges and loading them into tape drives for transferring data, such as said cartridge information, is time consuming and can lead to premature wear of the cartridges, the robot, the tape drives, and other components of the library. Another disadvantage of such conventional libraries is that diagnostic operations on the tape drives are manually performed by a technician who examines each tape drive, thereby increasing maintenance cost and duration.
There is, therefore, a need for a data storage library wherein selected information can be transferred to and from each cartridge without loading the cartridge into a tape drive. There is also, a need for such a library to include a communication interface for transferring data to each cartridge without loading the cartridge into a tape drive. There is also, a need for such a library to allow efficient and preferably automated diagnostics operations on the tape drives therein.
In one embodiment the present invention provides a method and digital data storage unit operating according to said method, that satisfy these needs. In one version, the digital data storage unit (data storage library) comprises: (a) a multiplicity of media storage slots for receiving a plurality of storage media units, each storage media unit including a storage medium and a memory device (MD) for storing data, the memory device including an interface for transferring data to and from the memory device; (b) one or more media data transfer devices physically distributed within the digital data storage unit in relation to the storage media slots for transferring data to and from the storage medium in each storage media unit; (c) a loader mechanism for selectively moving a storage media unit between a storage media slot and said media data transfer devices for transferring data to or from the storage medium in the storage media unit; (d) at least one memory data transfer device (MDTD) including a memory device interface for transferring data to and from the memory device of one or more storage media units; and (e) a controller within the digital data storage unit, configured for controlling the loader mechanism to move storage media units to said one or more media transfer devices for transferring data to and from the storage medium in each storage media unit.
The memory data transfer device further includes a controller interface for transferring data to and from the controller, and the controller further includes an interface for transferring data to and from the memory data transfer device. The controller is further configured for transferring data to and from the memory device of one or more storage media units via the memory data transfer device. In one version, the digital data storage unit further comprises a communication link for connecting the controller to an external system, wherein the controller is further configured for transferring data between the memory device of one or more storage media units and the external system using the memory data transfer device.
The digital data storage unit can further comprise a communication link connecting the controller to a host computer, wherein the controller is further configured for: (i) receiving and decoding a command sent by the host for access to a selected storage media unit to transfer data between the host computer and the memory device of the selected storage media, and (ii) transferring data between the host computer and the memory device of the selected storage media using the memory data transfer device.
In one version, the memory data transfer device can be supported by the loader mechanism, and the controller is further configured for controlling the loader mechanism for moving the memory data transfer device to a selected storage media unit in a storage media slot for transferring data between the memory data transfer device and the memory device in the storage media unit.
In another version of the digital data storage unit, the loader mechanism includes a gripper for gripping the memory data transfer device; the memory data transfer device is removably stored in the digital data storage unit; and the controller is further configured for controlling the loader mechanism for gripping and moving the memory data transfer device to a selected storage media unit for transferring data between the memory data transfer device and the memory device in the selected storage media unit.
Yet in another version of the digital data storage unit, the memory data transfer device is located in a storage location in the digital data storage unit; and the controller is further configured for controlling the loader mechanism to move one or more storage media units to said storage location for transferring data between the memory data transfer device and the memory device of each storage media unit.
In one example, such a digital data storage unit can comprise a tape library, wherein each storage media unit comprises a tape cartridge, and the storage media in the tape cartridge comprises magnetic tape; and each media data transfer device comprises a tape drive. According to the present invention, selected information can be transferred to and from each cartridge without loading the cartridge into a tape drive. The library includes a communication interface for transferring data to each cartridge without loading the cartridge into a tape drive. The library further allows efficient and preferably automated diagnostics operations on the tape drives therein.